1. Field of the Invention
This invention relates to sheet cutters and, more particularly, to a blade cutting assembly having a plurality of cutting blades which can be selectively placed in an operative position.
2. Background Art
Myriad designs currently exist for sheet cutters. In one common construction, a base is provided to support a stacked, plurality of sheet layers in an operative cutting position. A guide assembly, including an elongate guide rail, is mounted on the base. A blade cutting assembly is guided by the rail in a predetermined cutting path.
The cutting blade assembly supports a cutting blade in such a manner that the cutting blade penetrates the sheet layer(s) as the cutting blade assembly moves in the cutting path. The cutting blades generally have either a fixed configuration or a rotary configuration. In the former case, the cutting blade is typically cantilevered from a support. In the latter case, the cutting blade is typically disc-shaped and mounted for rotation about an axis. The disc-shaped blade may have different cutting edge configurations which allow either continuous straight or non-straight cut formation or perforate cut formation.
Regardless of their configuration, cutting blades are prone to being dulled after extensive use. Most cutters are designed to allow replacement of a cutting blade when this condition occurs or the cutting blade is damaged. Typically, the cutting blade assembly is designed to have a portion thereon that can be separated to allow access to, and replacement of, the active cutting blade. This requires that the user halt cutting operations, disassemble part of the cutting blade assembly, remove the active cutting blade, install a new cutting blade, and reassemble the portion of the cutting blade assembly. Aside from the lost time associated with this operation, the user is inconvenienced and required to handle cutting blades with sharp edges that could potentially inflict injury.
It is also common to interchange cutting blades with different cutting characteristics. For example, on a single sheet layer, it may be desirable to sever an edge of the sheet later to produce a particular size, and to thereafter form perforations on the same sheet layer. To operate on a sheet layer in this manner, the user is required to start with one cutting blade configuration, remove that blade and replace the same with a second configuration of blade after the first cutting operation is performed, and thereafter reinstall the blade with the first configuration. Depending upon the particular construction of the cutting blade assembly, this process may be quite time consuming and burdensome.
Ideally, cutting blades with the same or different configurations would be interchangeable readily and with a minimal time investment on a user's part. The industry continues to seek out sheet cutter designs with enhanced versatility and which facilitate operation by a user without creating an obtrusive structure, or one that becomes impractically expensive for the particular category of user at which it is targeted.